American Rare Earths Awards Whole of Property Development Assessment for Halleck Creek

Rhea-AI Summary

American Rare Earths (ADR: AMRRY) has awarded a Whole of Property Development Assessment (WPDA) for its 8,108-acre Halleck Creek rare earths project, with work starting in Q2 2026 and running through end-2026. The WPDA will integrate geology, metallurgy, mining and permitting to plan multi-phase development across Cowboy State, Red Mountain, Overton Mountain and Bluegrass.

Halleck Creek hosts ~2.63 billion tonnes in-situ and an estimated 8.64 million tonnes contained Total Rare Earth Oxide; Cowboy State shows a ~20-year mine life and a 0.383 strip ratio. The WPDA will use December 2025 processing test results to inform expansion scenarios and permitting pathways.

Positive

• In-situ resource of approximately 2.63 billion tonnes
• Estimated 8.64 million tonnes contained Total Rare Earth Oxide (TREO)
• Cowboy State mine life estimated at 20 years
• Very low strip ratio 0.383 at Cowboy State
• WPDA start in Q2 2026, completion targeted by end-2026
• December 2025 processing produced mixed rare earth oxide

Negative

• Project expansion requires state and federal permitting, including BLM land approvals

News Market Reaction – AMRRY

-1.66%

-1.66% Session close to close

In the Apr 7 session, AMRRY declined 1.66%, reflecting a mild negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

This announcement advances planning for the Halleck Creek district by commissioning a Whole of Prope...

Analysis

This announcement advances planning for the Halleck Creek district by commissioning a Whole of Property Development Assessment that integrates geology, mining, metallurgy and permitting across 8,108 acres and an in-situ resource of 2.63 billion tonnes. It builds on prior processing breakthroughs and recent pilot and study work. Investors may track progress toward the 2026 Pre‑Feasibility Study, mine planning at 5–10 Mtpa, and how the 8.64 million tonnes of contained TREO are phased into potential production.

Key Figures

Halleck Creek land package: 8,108 acres In-situ resource: 2.63 billion tonnes Cowboy State mine life: 20 years +5 more

8 metrics

Halleck Creek land package 8,108 acres Project area in Albany and Platte Counties, Wyoming

In-situ resource 2.63 billion tonnes Total in-situ mineral resource estimate at Halleck Creek

Cowboy State mine life 20 years Estimated mine life for Cowboy State Mine

Strip ratio 0.383 Estimated strip ratio for Cowboy State Mine

Wyoming ranking 4 Wyoming ranked number four globally for investment attractiveness

Development rate scenarios 5–10 Mtpa Conceptual mine plans and expansion throughput scenarios

Contained TREO 8.64 million tonnes Contained Total Rare Earth Oxide in Halleck Creek deposit

WPDA duration through end of 2026 Expected timeframe for Whole of Property Development Assessment

Historical Context

5 past events · Latest: Apr 01 (Positive)

Pattern 5 events

Date	Event	Sentiment	24h Move	Catalyst
Apr 01	Pilot plant plan	Positive	+1.7%	Acceleration of Halleck Creek pilot plant with strong concentrate test metrics.
Mar 30	Oxides to metals study	Positive	+4.5%	Engagement of Tetra Tech for heavy rare earth Oxides to Metals study.
Mar 25	Strategy VP hire	Positive	+5.6%	Appointment of Newmont veteran as VP Corporate Development and Strategy.
Mar 24	La Paz review	Positive	-2.3%	Engagement to review and rank gold, silver, copper, manganese targets at La Paz.
Mar 16	DoE feedstock deal	Positive	+2.2%	Selection of Halleck Creek ore as feedstock for DoE METALLIC consortium research.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Pattern Detected

Recent Halleck Creek–focused announcements have mostly seen positive price reactions, with one notable divergence on a La Paz exploration update.

Recent Company History

Over the past month, AMRRY has released a series of development-focused updates centered on Halleck Creek and broader project pipeline work. Announcements included commissioning a pilot plant with concentrate metrics, engaging an Oxides to Metals study for heavy rare earths, adding a corporate development executive, and supplying ore to the DoE METALLIC consortium. Most of these saw positive one-day moves between 1.73% and 5.59%, while a La Paz target review on Mar 24 coincided with a -2.33% reaction.

Key Terms

pre-feasibility study, section 232 investigation, rare earth oxides, mixed rare earth oxalate, +4 more

8 terms

pre-feasibility study technical

"completing the Halleck Creek Pre-Feasibility Study in 2026"

A pre-feasibility study is an initial assessment that evaluates whether a proposed project or investment idea is worth exploring further. It involves examining basic factors like costs, potential benefits, and possible challenges, similar to conducting a preliminary check before deciding to invest more time and resources. This helps investors determine if pursuing the project further is practical and likely to be successful.

section 232 investigation regulatory

"a subsequent Section 232 investigation that frame rare earths as a national security"

A Section 232 investigation is a U.S. government review that asks whether certain imports threaten national security and whether the president should limit those imports through tariffs, quotas or other restrictions. For investors, the outcome can act like a sudden border rule change that raises costs, disrupts supply chains or limits market access for affected industries, so it can quickly alter company profits and stock values.

rare earth oxides technical

"successfully produced rare earth oxides from Halleck Creek ore"

Rare earth oxides are compounds formed when rare earth elements combine with oxygen, creating powders or solids used as the raw ingredients for critical components like strong magnets, catalysts, display phosphors and some battery materials. They matter to investors because these materials are essential to many high‑growth industries and their supply is often concentrated and hard to scale, so shortages, production changes or cost swings can quickly affect manufacturers’ profits and stock values.

mixed rare earth oxalate technical

"produced both a mixed rare earth oxalate and a mixed rare earth oxide from purified"

A mixed rare earth oxalate is a solid chemical made when several rare earth elements are combined with oxalate ions; it looks like a powdery precipitate and serves as an intermediate step in turning mined rare earths into usable oxides and metals. For investors, it signals an early-stage product in the rare earth supply chain—its composition and purity affect the value, processing costs, and eventual supply of materials used in magnets, electronics and clean-energy technologies, much like crude lumber’s quality affects the price and usefulness of finished furniture.

leachate technical

"from purified leachate solution after impurity removal"

Leachate is the liquid that forms when water or other fluids pass through waste, soil, or stored materials and pick up dissolved chemicals, heavy metals, or biological contaminants—think of rainwater running through a used tea bag and carrying color and flavor with it. For investors, leachate matters because it signals potential pollution that can trigger cleanup costs, regulatory penalties, remediation obligations, and drops in property or asset value, affecting a company’s financial risk and liabilities.

flowsheet technical

"updated preliminary Pre-Feasibility Study flowsheet successfully produced rare earth oxides"

A flowsheet is a structured table that records a series of clinical or operational data points—such as vital signs, lab results, medication doses, procedures or milestone dates—so each patient or case can be tracked over time. For investors, a flowsheet turns detailed trial or operational activity into a clear timeline that highlights progress, gaps or problems, helping assess development speed, regulatory readiness and potential delays much like a trip log shows a journey’s pace and hiccups.

blm lands regulatory

"Map out permitting pathways and land-status considerations for BLM lands."

BLM lands are public federal lands managed by the U.S. Bureau of Land Management that are leased or permitted for uses like grazing, mining, oil and gas development, renewable energy projects, and recreation. For investors, these lands matter because access, leases, permits and regulatory decisions act like a landlord’s rules—controlling who can develop natural resources, how quickly projects can start, and what costs or restrictions apply, all of which affect project value and risk.

total rare earth oxide technical

"some 8.64 million tonnes of contained Total Rare Earth Oxide6"

Total rare earth oxide (TREO) is the combined percentage of all rare earth elements in a mineral sample, reported as if each element were its oxide form; it’s the standard way miners and buyers state how much valuable material is present. Investors watch TREO because higher percentages mean a richer, more marketable deposit or concentrate—like knowing the sugar content tells you how sweet a fruit—affecting potential revenue, processing costs and product value.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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DENVER, April 07, 2026 (GLOBE NEWSWIRE) -- American Rare Earths (ASX: ARR | OTCQX: ARRNF | ADR: AMRRY) (“ARR” or the “Company”) is pleased to announce that it has awarded a Whole of Property Development Assessment (“WPDA”) for its flagship Halleck Creek rare earths project in Wyoming to a major engineering firm, with work scheduled to commence in Q2 2026.

The WPDA is a planning level, desktop study that will integrate all existing geological, metallurgical, mining and permitting data across ARR’s entire 8,108-acre Halleck Creek land package in Albany and Platte Counties, Wyoming. The assessment will build on the Phase 1 Cowboy State Mine plan and establish a strategic roadmap for subsequent expansion phases at Red Mountain, Overton Mountain and Bluegrass.

Halleck Creek – a world-scale Wyoming asset

Halleck Creek hosts a total in-situ mineral resource estimate of approximately 2.63 billion tonnes of ore¹, providing scope for long term, multi-generational potential production under current scoping level development assumptions². The Cowboy State Mine alone has an estimated mine life of 20 years and very low strip ratio of 0.38³.

The CEO’s letter to shareholders dated 9 February 2026⁴ highlighted Halleck Creek as a very large, long-life rare earth deposit located in one of the world’s most attractive mining jurisdictions, with Wyoming ranked number four globally for overall investment attractiveness in the Fraser Institute’s July 2025 survey. The WPDA is designed to fully leverage this combination of scale and jurisdictional advantage by optimizing how the broader Halleck Creek district is developed over time.

_______________
¹ Refer ASX announcement dated 4 February 2025
² Refer ASX announcement dated 24 February 2025
³ Refer ASX announcement dated 24 February 2025
⁴ Refer ASX announcement dated 9 February 2026

Purpose and benefits of the Whole of Property Development Assessment

The WPDA will:

• Synthesize existing geological, metallurgical and economic data from the Cowboy State Mine, Red Mountain, Overton Mountain and Bluegrass areas into a unified project-wide model.
• Compare resource areas on grade, strip ratio, resource confidence, metallurgical characteristics and infrastructure proximity to determine which zones should be prioritized in future phases.
• Develop conceptual mine plans and expansion scenarios at 5–10 Mtpa, assessing mine-life extension options and cumulative resource utilization across the entire property.
• Map out permitting pathways and land-status considerations for BLM lands.

By integrating these workstreams, the WPDA will give ARR a clearer view of how to sequence development of the largest known deposit of total contained rare earth oxides in North America, and how to scale production from a state-permitted Wyoming base toward multi-phase district development in response to U.S. demand and policy support.

Alignment with CEO strategy and U.S. critical minerals policy

In his letter to shareholders, CEO Mark Wall set out a strategy focused on: completing the Halleck Creek Pre-Feasibility Study in 2026, advancing state permitting for the Cowboy State Mine, scaling processing to produce meaningful product volumes, and positioning Halleck Creek as a cornerstone of a secure U.S. rare earths supply chain. He also noted increasing U.S. policy support, including a March 2025 executive order and a subsequent Section 232 investigation that frame rare earths as a national security imperative and seek to accelerate domestic critical minerals projects.

The WPDA directly supports this strategy by:

• Providing the potential technical and economic basis to extend the Cowboy State Mine into a much larger multi-phase operation across state and federal lands, consistent with the Company’s ambition to secure U.S. critical mineral independence for generations.
• Informing long-term capital planning and helping prioritize investments that enhance scale, optionality and returns, in line with the CEO’s commitment to disciplined capital allocation and potential U.S. listing considerations.
• Supporting engagement with state and federal stakeholders by clearly articulating how Halleck Creek can be expanded in a responsible, staged manner from its Wyoming base to meet growing U.S. defense and technology demand.
  

Building on the December 2025 technical breakthrough

The WPDA follows ARR’s December 2025 technical breakthrough⁵, in which the updated preliminary Pre-Feasibility Study flowsheet successfully produced rare earth oxides from Halleck Creek ore. Using the refined mineral processing flowsheet, the Company produced both a mixed rare earth oxalate and a mixed rare earth oxide from purified leachate solution after impurity removal, demonstrating a clear path from ore to saleable rare earth products.

That breakthrough, described by the CEO as the type of technical work that moves a project from promise toward production, provides the processing assumptions and recovery parameters that will underpin the WPDA’s analysis of future phases across Red Mountain, Overton Mountain and Bluegrass.

_______________
⁵ Refer ASX announcement dated 16 December 2025

Next steps

The WPDA is expected to run through to the end of 2026, with key milestones including data compilation and verification, integrated geological synthesis, resource-area comparison, mine-planning scenarios and development sequencing.

American Rare Earths CEO Mark Wall commented “This work is a critical step in unlocking the full potential of the largest domestic United States rare earth deposit with some 8.64 million tonnes of contained Total Rare Earth Oxide⁶ and advancing our strategy to become a cornerstone of the United States rare earths supply chain.”

This release was authorized by the Board of American Rare Earths.

Investors can follow the Company’s progress at www.americanree.com.

About American Rare Earths Limited:  

American Rare Earths (ASX: ARR | OTCQX: ARRNF | ADR: AMRRY) is a critical minerals company at the forefront of reshaping the U.S. rare earths industry. Through its wholly owned subsidiary, Wyoming Rare (USA) Inc. (“WRI”), the company is advancing the Halleck Creek Project in Wyoming—a world-class rare earth deposit with the potential to secure America’s critical mineral independence for generations. Located on Wyoming State land, the Cowboy State Mine within Halleck Creek offers cost-efficient open-pit mining methods and benefits from streamlined permitting processes in this mining-friendly state.  

With plans for onsite mineral processing and separation facilities, Halleck Creek is strategically positioned to reduce U.S. reliance on imports—predominantly from China—while meeting the growing demand for rare earth elements essential to defense, advanced technologies, and economic security. As exploration progresses, the project’s untapped potential on both State and Federal lands further reinforces its significance as a cornerstone of U.S. supply chain security. In addition to its resource potential, American Rare Earths is committed to environmentally responsible mining practices and continues to collaborate with U.S. Government-supported R&D programs to develop innovative extraction and processing technologies for rare earth elements.

_______________
⁶ Refer ASX announcement dated 4 February 2025

For more information:

Company Contact:

Nick Lissolo, Vice President Corporate Development and Strategy

nlissolo@americanree.com

Media Contact:

Susan Assadi
sassadi@americanree.com
347 977 7125

Investor Relations US Contact:

Beverly Jedynak
Beverly.jedynak@viriathus.com
312 943 1123

FAQ

What is the scope of American Rare Earths' WPDA for Halleck Creek (AMRRY)?

The WPDA is a project-wide desktop assessment integrating geology, metallurgy, mining and permitting. According to the company, it will unify data across 8,108 acres to prioritize zones, develop 5–10 Mtpa scenarios, and define permitting pathways for state and federal lands.

When will the Halleck Creek WPDA for AMRRY start and finish?

Work is scheduled to commence in Q2 2026 and run through to the end of 2026. According to the company, key milestones include data compilation, integrated synthesis, resource comparison, mine-planning scenarios and development sequencing.

How large is the Halleck Creek resource cited by American Rare Earths (AMRRY)?

Halleck Creek hosts approximately 2.63 billion tonnes of in-situ ore and about 8.64 million tonnes contained TREO. According to the company, these figures underpin multi-phase development potential and long-life production planning.

What were the December 2025 technical results that support the WPDA for AMRRY?

The company produced a mixed rare earth oxalate and mixed rare earth oxide from Halleck Creek ore using an updated flowsheet. According to the company, these results provide processing assumptions and recovery parameters for future phase analyses.

What does the Cowboy State Mine metric mean for AMRRY investors?

Cowboy State has an estimated 20-year mine life with a low strip ratio of 0.383, indicating long-duration, lower-waste mining potential. According to the company, these metrics support staged scaling from a state-permitted Wyoming base.

How will the WPDA support American Rare Earth's strategy and US policy goals (AMRRY)?

The WPDA aims to provide technical and economic basis for multi-phase expansion aligned with U.S. critical minerals policy. According to the company, it will inform capital planning, stakeholder engagement, and sequencing to meet domestic rare earth demand.